Roller arrangement for embossing web-shaped materials

ABSTRACT

A roller arrangement for embossing web-shaped materials, in particular, web-shaped paper and tissue materials, is disclosed. A roller arrangement comprises a punch, which includes a first embossing pattern, containing a plurality of spaced-apart elevations, and a matrix which includes a second embossing pattern, containing a plurality of spaced-apart elevations. The elevations on the first embossing pattern can be lowered into free spaces in between elevations of the second embossing pattern. Elevations on embossing patterns on punches and matrixes are positioned in rows spaced apart in a circumferential direction. At least one cleaning roller is provided, which comprises cleaning elements arranged in a circumferential direction that interact with a punch or a matrix in between rows of elevations on embossing patterns of punches and matrixes.

This application is a national stage application of InternationalApplication No. PCT/DE2004/001920, filed Aug. 31, 2004, which is hereinincorporated by reference in its entirety.

BACKGROUND

1. Field of the Invention

The present invention relates generally to embossing. More particularly,embodiments of the present invention relate to an apparatus for cleaningdeposits on an embossing roller during an embossing process.

2. Background of the Invention

Embossing is a popular technique for creating three-dimensional designson or creating textures in substrates, such as web-shaped paper ortissue material. To emboss a substrate, an embossing pattern on anembossing roller rolls over a substrate, for example tissue paper, andthe embossing pattern breaks fibers in the paper. During embossing,sediment, such as paper fibers and dust, adhere to gaps within embossingpatterns, which seriously contaminate embossing rollers. One solution tothis problem is to halt production to allow for cleaning of embossingrollers. Another solution to address this problem includes complexdevices that require spraying water or solvent on embossing rollers towash away sediment. Such solutions are costly or can lead to largerdifficulties such as clogging of embossing rollers. Consequently, a needexists for a cost-effective and design-effective device for embossingweb-shaped materials that remains clean of sediment during operation.

BRIEF SUMMARY OF THE INVENTION

The present invention is directed toward a roller arrangement forembossing web-shaped materials that allows for cleaning duringoperation. An embodiment of the present invention provides a rollerarrangement for embossing web-shaped materials, such as web-shaped paperand tissue materials, comprising at least one embossing roller and acleaning roller. An embossing pattern of a plurality of elevations isdisposed on the embossing roller. A plurality of cleaning elements isdisposed on the cleaning roller. The embossing roller can compriseeither a punch or a matrix.

Another embodiment of the present invention includes a punch, a matrix,and a cleaning roller. A first embossing pattern of a plurality ofelevations is disposed on the punch. A second embossing pattern of aplurality of elevations is disposed on the matrix. A plurality ofcleaning elements is disposed on the cleaning roller. Elevations ofpunches and matrixes and cleaning elements can be aligned in rows spacedapart in a circumferential direction. Elevations of the first embossingpattern can be arranged such that they can be lowered into free spacesbetween elevations of the second embossing pattern. Cleaning elements ofthe cleaning roller can be arranged in such a way to allow interactionwith a punch or a matrix. Interaction between cleaning elements andelevations of a punch or a roller can occur in between rows of theelevations. This configuration allows the cleaning elements to removesediment collecting in between rows of elevations of punches andmatrixes.

Another embodiment of the present invention provides a method forembossing web-shaped material by running an embossing roller onweb-shaped material, where a plurality of elevations are arranged on theembossing roller in rows that are spaced apart in a circumferentialdirection. A cleaning roller is positioned adjacent to the embossingroller, where a plurality of cleaning elements are aligned on thecleaning roller to fit in between the rows of the embossing roller. Theplurality of cleaning elements run in between the rows of the embossingroller to remove sediment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing an exemplary punch in accordancewith a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing an exemplary cleaning roller thatcan interact with a punch such as that embodied in FIG. 1.

FIG. 3 is a schematic diagram showing an exemplary punch in accordancewith a second embodiment of the present invention.

FIG. 4 is a schematic diagram showing an exemplary cleaning roller thatcan interact with a punch such as that embodied in FIG. 3.

FIG. 5 is a schematic diagram showing an exemplary path of cleaningelements embodied in FIG. 2 between elevations on a punch such as thatembodied in FIG. 1.

FIG. 6 is a schematic diagram showing an exemplary path of cleaningelements embodied in FIG. 4 between elevations on a punch such as thatembodied in FIG. 3.

FIG. 7 is a schematic diagram showing an exemplary punch in accordancewith a third embodiment of the present invention.

FIG. 8 is a schematic diagram showing an exemplary cleaning roller thatcan interact with a punch such as that embodied in FIG. 7.

FIG. 9 is a schematic diagram showing an exemplary path of cleaningelements embodied in FIG. 8 between elevations on a punch such as thatembodied in FIG. 7.

DETAILED DESCRIPTION OF THE INVENTION

An embodiment of the present invention provides a roller arrangement forembossing web-shaped materials, such as web-shaped paper and tissuematerials, comprising at least two embossing rollers and at least onecleaning roller. An embossing roller can be either a punch or a matrix.A punch includes a first embossing pattern with a plurality ofspaced-apart elevations. A matrix includes a second embossing patternwith a plurality of spaced-apart elevations. Elevations on the firstembossing pattern can be lowered into free spaces on the secondembossing pattern.

When a first embossing pattern and a second embossing pattern of a punchand matrix are geometrically adjusted on top of each other in such a waythat elevations mutually and substantially correspond at a number oflocations, micro-fissure embossing is possible. The first and secondembossing patterns break fibers of a web-shaped material, thus greatlyincreasing the water absorbency capability of the fibers. Duringembossing of web-shaped materials, such as web-shaped paper and tissuematerials, sediment such as paper fiber and dust, adhere to gaps withinembossing patterns, which can seriously contaminate punches andmatrixes.

In accordance with an embodiment of the present invention, elevations onan embossing pattern of a punch or matrix are arranged in rows that arespaced apart in a circumferential direction. Elevations on an embossingpattern can also be arranged in a checker board pattern. For example,elevations could, when seen from a top view, be cross-, square-,oval-shaped or shaped in other similar configurations, as long as adesired micro-fissure embossing is achieved as a punch and matrixinteract.

In accordance with an embodiment of the present invention, at least onecleaning roller is provided, which comprises cleaning elements that canbe arranged in a circumferential direction that can run between rows ofelevations on embossing patterns of punches or matrixes. Cleaningelements can be knife-like cleaning studs of such a geometry to conformto a geometry of an embossing pattern. A punch or a matrix can be fittedwith a cleaning roller that can be located outside a path of aweb-shaped material to allow interaction with the punch or the matrix.During operation, cleaning elements continuously run in acircumferential direction between elevations on each embossing pattern,cleaning out sediment such as paper fibers and dust.

Because cleaning elements run in a circumferential direction of acleaning roller, the cleaning roller itself is cleaned. Cleaningelements can also be radially offset in an axial direction of a cleaningroller to guarantee smooth operation of a cleaning roller by preventingcleaning elements of a cleaning roller from colliding with elevations ofa punch or a matrix.

FIG. 1 is a schematic diagram showing an exemplary punch 10 inaccordance with a first embodiment of the present invention. Punch 10 isfitted with an embossing pattern that includes elevations 16 arranged inrows 12 and 14 in a circumferential direction, which can be identicaland cross shaped, when seen from above, whereby elevations 16 also arearranged in a checker board pattern.

FIG. 2 is a schematic diagram showing an exemplary cleaning roller 20that can interact with punch 10 embodied in FIG. 1. Several cleaningelements 26, 26′ and 28 are arranged in rows 22 and 24 in acircumferential direction on cleaning roller 20. Cleaning elements 26and 26′ of each row are spaced apart in a circumferential direction sothat the cleaning function is briefly interrupted during operation,which prevents cleaning elements 26 and 26′ from clogging as they passvery closely by elevations 16. During interruption, collected paperfibers can be removed from in between cleaning elements 26 and 26′ andthe cleaning roller 20. Cleaning elements 26 and 28 are radially spacedapart in an axial direction of a cleaning roller 20 in such a way thatcleaning elements 26 and 28 successively run between spaced apart rowsof elevations 16, preventing collisions between cleaning elements ofcleaning roller 20 and elevations of punch 10. Cleaning elements 26 and28 are radially offset in such a way that only one cleaning element 16at any one time runs on an axial line of a cleaning roller 20.

FIG. 3 is a schematic diagram showing an exemplary punch 30 inaccordance with a second embodiment of the present invention. Punch 30can be fitted with elevations 36 arranged in rows 32 and 34 in a checkerboard pattern, where the distance between the rows of elevations 32 and34 is greater than the distance between the rows of elevations 12 and 14in another embodiment of the present invention shown in FIG. 1.

FIG. 4 is a schematic diagram showing an exemplary cleaning roller 40that can interact with punch 30 embodied in FIG. 3. Cleaning roller 40is fitted with wider cleaning elements 46, 46′, and 48 than cleaningelements 26, 26′, and 28, shown in FIG. 2, such that paper fibers anddust collected between rows of elevations 32 and 34 are gathered.

FIG. 5 is a schematic diagram showing an exemplary path A of cleaningelements 26, 26,′ and 28 on cleaning roller 20, embodied in FIG. 2,between elevations 16 on punch 10 embodied in FIG. 1. By geometricallycomplementing shapes of elevations 16 with dimensions of cleaningelements 26, 26′, and 28, fibers and dust can be removed from surfacesof embossing rollers to facilitate superior embossing results.Similarly, FIG. 6 is a schematic diagram showing an exemplary path B ofcleaning elements 46, 46′, and 48 on cleaning roller 40 embodied in FIG.4, between elevations 36 on punch 30 embodied in FIG. 3.

FIG. 7 is a schematic diagram showing an exemplary punch in accordancewith a third embodiment of the present invention. FIG. 7 shows a patternof regularly spaced-apart and substantially rectangular elevations 50whose circumferential contour is slightly convex. FIG. 8 is a schematicdiagram showing an exemplary cleaning roller that can interact with apunch such as that embodied in FIG. 7. Cleaning studs 52 that can run ina circumferential direction can be fitted with horizontally runningelement segments 54 that correspond with spaced-apart elevations 50, asshown in FIG. 7, of a punch, whereby axially neighboring elementsegments 54 are separated by a free space 56. FIG. 9 is a schematicdiagram showing an exemplary path of cleaning elements embodied in FIG.8 between elevations on a punch embodied in FIG. 7.

Although FIGS. 1-7 illustrate the present invention as applied to apunch, one of ordinary skill in the art would readily appreciate thatthe cleaning roller of the present invention could be applied in asimilar manner to a matrix. Indeed, as stated above, cleaning elementscan cooperate with either punches or matrixes, or both.

The foregoing disclosure of the preferred embodiments of the presentinvention has been presented for purposes of illustration anddescription. It is not intended to be exhaustive or to limit theinvention to the precise forms disclosed. Many variations andmodifications of the embodiments described herein will be apparent toone of ordinary skill in the art in light of the above disclosure. Thescope of the invention is to be defined only by the claims appendedhereto, and by their equivalents.

1. A roller arrangement for embossing a web-shaped material, comprising: at least one embossing roller defining an embossing pattern, wherein the embossing pattern comprises a plurality of elevations aligned in rows that are spaced apart in a circumferential direction; and a cleaning roller defining a plurality of cleaning elements that are aligned between the rows of the at least one embossing roller.
 2. The roller arrangement of claim 1, wherein the at least one embossing roller comprises a punch.
 3. The roller arrangement of claim 1, wherein the at least one embossing roller comprises a matrix.
 4. A roller arrangement for embossing a web-shaped material, comprising: a punch defining a first embossing pattern, wherein the first embossing pattern comprises a first plurality of elevations aligned in rows that are spaced apart in a circumferential direction; a matrix defining a second embossing pattern, wherein the second embossing pattern comprises a second plurality of elevations aligned in rows that are spaced apart in a circumferential direction; and a cleaning roller defining a plurality of cleaning elements that are aligned between the rows of one of the punch and the matrix.
 5. The roller arrangement of claim 4, wherein the plurality of elevations of the first embossing pattern is configured to align with free spaces between the plurality of elevations of the second embossing pattern.
 6. The roller arrangement of claim 4, wherein the cleaning elements are aligned in a circumferential direction of the cleaning roller.
 7. The roller arrangement of claim 4, wherein the cleaning elements interact with the one of the punch and the matrix in between the rows of elevations of the one of the punch and the matrix to remove sediment.
 8. The roller arrangement of claim 4, wherein the cleaning elements are spaced apart in the circumferential direction of the cleaning roller.
 9. The roller arrangement of claim 8, wherein the cleaning elements are radially offset in the axial direction of the cleaning roller.
 10. The roller arrangement of claim 4, wherein the plurality of elevations of at least one of the first and second embossing patterns of the punch and matrix is arranged in a checker board pattern.
 11. The roller arrangement of claim 4, wherein the web-shaped material is tissue material.
 12. The roller arrangement of claim 4, wherein the web-shaped material is paper.
 13. The roller arrangement of claim 4, wherein one of the first embossing pattern and the second embossing pattern is cross-shaped.
 14. The roller arrangement of claim 4, wherein one of the first embossing pattern and the second embossing pattern is square-shaped.
 15. The roller arrangement of claim 4, wherein one of the first embossing pattern and the second embossing pattern is oval-shaped.
 16. A method for embossing web-shaped material comprising: rolling the web-shaped material over an embossing roller, the embossing roller defining a plurality of elevations in rows that are spaced apart in a circumferential direction; positioning a cleaning roller adjacent to the embossing roller, the cleaning roller defining a plurality of cleaning elements that are aligned between the rows of the embossing roller; and running the plurality of cleaning elements in between the rows of the embossing roller to remove sediment.
 17. The method of claim 16, further comprising running the plurality of cleaning elements intermittently in between the rows of the embossing roller to remove sediment.
 18. The method of claim 16, further comprising arranging the plurality of cleaning elements radially offset on the cleaning roller such that only one cleaning element at any one time runs between the rows of the embossing roller.
 19. The method of claim 16, further comprising running the plurality of cleaning elements successively between the rows of the embossing roller.
 20. The method of claim 16, wherein the embossing roller comprises one of a punch and a matrix. 